Something's wrong with something you entered for one (or both) of the 1098s, but I can't figure out exactly what it might be.
Run Smart Check to see if TurboTax finds any errors in your tax return.
Carefully review your entries for both 1098 forms, and your answers to all of the questions following the entry of each 1098. Read the questions carefully, and pay particular attention to the questions about which is the most recent 1098. The 1098 from Bank 2 would be the most recent.
Are you using TurboTax Online or the desktop TurboTax software? If you are using the desktop software, don't make any entries about mortgage interest in forms mode. Use the Step-by-Step interview.